VENTURA, Calif. (CN) – After a week and 242,500 acres, the Thomas Fire burning in Ventura and Santa Barbara counties is now the fourth largest wildfire in California history, according to Cal Fire.

The fire is only 30 percent contained and could grow as high winds continue to fan flames throughout the region. Red flag warnings are in effect through Friday morning, according to the Ventura County Fire Department.

A total of 8,144 firefighters are working to contain the blaze that sparked north of Santa Paula in Ventura County on Dec. 4. The cost to fight the fire as of Thursday morning is approximately $74.7 million dollars.

Cal Fire said 729 homes have been destroyed. Another 175 have been damaged and 18,000 structures are in the path of danger.

The agency also said 32-year-old Cory Iverson of Escondido died Thursday near Fillmore in Ventura County while fighting the Thomas Fire. He was an 8-year veteran of Cal Fire.

He is survived by his wife, Ashley, who is pregnant, their two-year-old daughter, Evie; mother, Denise Butler; stepfather, Scott Butler; and father, Craig Iverson, according to Cal Fire.

In a statement, Gov. Jerry Brown said, “Anne and I are saddened by Engineer Cory Iverson’s tragic death. His bravery and years of committed service to the people of California will never be forgotten.”

The fire has also spurred legal action: the first putative class action was filed Wednesday against Southern California Edison claiming the utility failed to maintain trees and vegetation around its power lines, and that’s what caused the fire.

According to Cal Fire, the cause of the wildfire remains under investigation.

Evacuation orders have been lifted for portions of Ojai, Santa Paula and the city of Ventura. In Santa Barbara County evacuation orders are in effect for Carpinteria and nearby communities. All schools in southern Santa Barbara County are closed through the end of the week and more than a dozen schools remain closed in Ventura County.

The National Weather Service in Los Angeles asks residents in Ventura and southeast Santa Barbara counties to close their vents and stay indoors to avoid the smoke. Health officials recommend anyone who must go outdoors to wear air masks.

At 60 miles long and 40 miles wide, the Thomas Fire is burning through the footprint of previous wildfires that burned throughout the region, according to the Ventura County Fire Department.

Meanwhile, state officials said they will do more controlled burns in 2018 to rid forests of fuel after what has been the costliest fire season in state history. They hope the effort will ease concern over 129 million dead and dying trees – victims of the recent drought and a bark beetle infestation – and escalating fire-suppression costs.